This invention relates generally to orienting objects and particularly to a device for orienting a substantially rectangular object on a substantially flat surface.
There are many instances in industry when it is necessary to accurately orient and locate a substantially rectangular object on a flat surface. An example of such an instant is the production of the phosphor screen on the inside surface of a kinescope faceplate panel. The phosphor screens of kinescopes are composed of triads of phosphors each of which emits a different color of light when impacted by electrons. The screens are produced by coating the internal surface of the faceplate panel with a slurry containing one of the phosphors and a light sensitive material. An apertured shadow mask is inserted into the panel and the panel is placed upon an exposure mechanism, commonly called a lighthouse. The lighthouse includes a bright light source which exposes the slurry through the apertures in the shadow mask. This process is repeated for each of the three phosphors. During the operation of a kinescope, electron beams are scanned across the shadow mask and the apertures cause the electron beams to impact a phosphor of the proper color. For this reason, it is critical that the panel be properly oriented and located on the lighthouse during the exposure process because the light passing through the apertures simulates the electron beams passing through the apertures during the operation of the tube. The present invention is directed to a device for accurately orienting and locating a faceplate panel on the flat surface of a lighthouse.